This invention relates to certain carbostyril compounds and to pharmaceutically acceptable salts thereof which are useful as cardiotonic agents, processes for preparing the same, and pharmaceutical compositions containing the carbostyril compounds or salts thereof.
Various carbostyril compounds are known which have hypotensive, blood platelet coagulation inhibitory or antiallergic activity as described in Japanese Patent Application (OPI) Nos. 130589/79, 135785/79, 138585/79, 141785/79, 76872/80, 49319/80, 53283/80, 53284/80 and 83781/80 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application").
Further, EP-A1-7525 and EP-A1-8014 describe isoquinoline compounds which have cardiac and circulatory activities.
However, the carbostyril compounds of this invention are structurally different from the conventional carbostyril and isoquinoline compounds.